chore: bump node version to 24 (lts)

[efekrskl]

Bumps node version to current LTS (24)

Checklist

• run npm run test && npm run benchmark --if-present
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

[Fdawgs]

@Eomm Not sure this a good comparison as Fastify v5 is still targetting Node 20 at minimum?

[Eomm]

@Eomm Not sure this a good comparison as Fastify v5 is still targetting Node 20 at minimum?

Why it is not a good comparison?
If someone starts using Fastify today, it is likely it will use the latest stable node.js version instead of the maintenance one.

I'm not saying we need to run the bench for every node.js version, but this showcase project should aim for the latest improvements IMHO